Dr. Paul's Research Perspectives
Through choices private and public,
our children’s future is in our hands
Ag chemicals in food and water are having profound, generational impacts through subtle effects.

By Paul Hepperly, PhD

editors' NOTE:

As New Farm Research and Training Manager at The Rodale Institute®, Dr. Paul Hepperly has been a regular contributor to NewFarm.org for some time, providing research updates, op-ed pieces, and white papers on topics like carbon sequestration in organic farming systems.

None of those venues do full justice to the range of Paul's experience, however. Paul grew up on a family farm in Illinois and holds a Ph.D. in plant pathology, an M.S. in agronomy and a B.S. in psychology from the University of Illinois at Champaign-Urbana. He has worked for the USDA Agricultural Research Service, in academia, and for a number of private seed companies, including Asgrow, Pioneer, and DeKalb. He has overseen research in Hawaii, Iowa, Puerto Rico, and Chile, and investigated such diverse crops as soybeans, corn, sorghum, sunflowers, ginger, and papaya. He has witnessed the move toward biotech among the traditional plant breeding community and the move toward organics among new wave of upcoming young farmers. Beford coming to the Rodale Institute Paul worked with hill farmers in India to help them overcome problems with ginger root rot in collaboration with Winrock Intermational.

Now we've decided to give Paul his own column, in which he can report on agricultural research from around the world and reflect on its relevance to The Rodale Institute's research program and to the progress of sustainable agriculture more generally in light of his own broad perspective. Enjoy.

How to contact Paul

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611 Siegfriedale Rd.
Kutztown, PA 19530

Posted May 12, 2006: A while back a group of medical researchers in the Seattle area started to measure the concentration of organophosphorus insecticides in the urine of pre-school children. Most children had sizable concentrations well over FDA recommended safe levels. Given what we are learning, I wonder if we scientists really know enough to set a “safe toxic level” for kids confident that it will still seem “safe” in the coming decades.

As in many scientific investigations, a few children were found to be atypical. In this case, their toxic levels were way under the rest of the kids measured. Interviewing the parents of these rare cases, researchers learned that their parents chose certified organic foods for the kids. With this tantalizing lead, the researchers expanded their trial to evaluate equal numbers of children eating conventional and organic diets. Again measuring urine samples, they found a whopping eight-fold increase of organophosphate contamination in the conventional non-organic group compared to the organic children.

These findings point to the importance of how food is produced and how the exposure to synthetic chemistry varies accordingly. Parents worried about their children’s exposure to contaminants can take measures to help protect their brood by lessening and eliminating these unnecessary toxic exposures. Eating organically certified food or food you produce yourself without chemical inputs is a rational protective step with benefits confirmed through rigorous scientific study.

Organophosphorus (also called organophosphate) insecticides were originally developed in Germany during World War II. They act to inhibit acetyl cholinesterase, an enzyme fundamental for nerve transmission in humans, other mammals and insects. It takes a much higher dose to kill a human than to kill a bug, but death by herbicide poisoning is not the only problem. There is robust scientific literature showing the ability of organophosphates to impact human developmental activity at far below lethal doses, due in part to these compounds' tendency to bio-accumulate within animals.

Our regulatory system mostly ignores the long-term effects of agrichemicals as our bodies encounter their residues. Noted University of Wisconsin animal scientist Warren Porter has shown that sub-toxic developmental effects of agrichemicals and mixtures that form synergistic damage are the Achilles Heel of the environmental regulatory system.

Organic farmers and consumers make many decisions to put health first in how to farm and what to eat. Why would we willingly throw the dice with our personal health or that of our family?

Porter points out that humans have the ability to de-toxify synthetic chemical residues only after puberty. This is because a child’s liver lacks key enzymes for this mission. Parents, nutritionists and policymakers need to make food choices realizing that children are much more vulnerable to chemical assault than are adults, and will accumulate toxic substances over a longer timeframe.

Dr. Elizabeth Guillette from the University of Florida has studied the influence of agrichemicals on the development of the Yaqui Indians children in Mexico. She identified within the Yaqui tribe one group which had accepted the introduction of chemical agriculture and has resided in a valley where it is practiced extensively. Another Yaqui group moved up into the surrounding hills to practice traditional lifestyles, avoiding chemical agriculture.

Guillette’s studies identified that the chemically exposed valley children lagged in every measurement of development including coordination, learning and memory. Many of the valley children could not draw the basic elements of a human even at 4 and 5 years old, putting them into a group of people believed to have little or no potential to develop appreciable social skills. The following illustration shows typical examples of the drastic developmental difference associated with valley (chemically exposed) and hill people who were largely unexposed to chemical agriculture.

Image courtesy Elizabeth Guillette
Used with permission.

Atrazine, the most-applied corn herbicide in the U.S., is infamous for washing into our surface and ground water, its persistence for years in our soil and even its ability to invade our atmosphere. Although this chemical is agriculturally banned in Switzerland (where it was discovered and is manufactured), we still apply millions of pounds annually throughout North America.

Scientific studies such as The Rodale Institute Farming Systems Trial regularly show that atrazine is routinely found in water at rates well over the EPA regulatory level. More importantly, research led by Tyrone Hayes at the University of California shows that exposure to even 1/30th of the regulatory dose changes male frogs into hermaphrodites. It is critical to note that ambiguous sexual development in humans is an epidemic in the United States. (You may not be aware of the epidemic in birth defects we are having, but from 1978 to 1993 the rate increased more than 5 times.)

A bright spot in this area is the finding that folic acid can reduce spina bifida by 75 percent if administered to a mother one month before or after conception. Information is now pointing to nitrates as sources of superoxidants which cause the spinal lesions of spina bifida. Folic acid seems to work as an anti-oxidant antidote to the reactive chemistry causing the lesions. Atrazine and nitrate invade our water system from herbicide and fertilizer use, respectively, in corn. (Both are also common lawn chemicals.)

Even as evidence mounts showing how pesticides impact human health, the industry has yet to own up to the full extent of its responsibility. One measure of this disparity of what we know medically and how we have yet to act in public policy is the fact that many doctors recommend against breast feeding due to the high level of toxins within breast milk.

The acknowledged negative impacts of agri-chemistry are accommodated in current regulations because, regulators say, overall societal benefits outweigh the risks. Unfortunately food consumers, not sufficiently aware of all the dangers of agriculture chemistry, take the risks, while the agrichemical industry derives the profits. We have yet to see an agrichemical interest step forward to clean up any of the contamination to our soil, water or air.

The proliferation of 10,000 registered chemicals which are tested mostly by the chemical industry itself does not guarantee our children’s safety. To the contrary, under the present system it guarantees that our children will have multiple and repeated exposures to known toxic components.

The good news is that more food grown with fewer chemicals is becoming more accessible in North America, week by week. Parents, especially, are seeking out certified organic food and other foods identified as being more healthful. Currently about half of the parents in North Americ—and more than 75 percent of European parents—are opting for organic baby food. While this phase lasts for a short period in a child’s life, it’s an important time and signifies a commitment by parents safeguard their young ones.

Both the Seattle parents who served organic food and the traditional Yaqui who literally took to the hills to avoid agricultural chemicals show the wisdom of being proactive for healthy food. The future of your children—and the farmers who want to raise their food—depends on it.